The present disclosure relates to a flushing unit, and more particularly, to a flushing unit cap assembly particularly suited for flushing vapor compression systems, such as HVAC and refrigeration systems.
Air conditioning and other systems require periodic flushing of refrigerants and/or contaminants such as during retrofits, refrigerant conversions and compressor burnouts, as well as for periodic maintenance. Non-flammable flushing solvents are typically used, that are generally compatible with CFC and HFC refrigerants and compressor oils. Such solvents must comply with stringent EPA Significant New Alternatives (SNAP) standards, and are capable of removing particulates, sludge, residue oil, moisture and acid from line sets and other system components.
For example, replacement of an air conditioner or heat pump and the concominant upgrade from R-22 to R-410A refrigerant can cause compatibility problems, as the mineral oil used in R-22 systems is not compatible with the R-410A refrigerant and oil. R-22 is a hydrochlorofluorocarbon (HCFC), and the presence of chlorine results in the HCFC having an affinity for mineral oil. In contrast, R-410A is a hydrofluorocarbon (HFC) and has no affinity for mineral oil. Any mineral oil remaining in the system tends to hang up in the refrigerant lines and other system components. This reduces efficiency and can cause unwanted chemical reactions with R-410A refrigerant. It is also important to rid the system of moisture, since moisture can break down the synthetic oil used with R-410A and minimize or eliminate its lubrication properties, causing the compressor to fail.
Accordingly, systems have been developed that allow for the quick and easy flushing of HVAC and refrigeration system line sets and system components with flushing agents under pressure. However, safety concerns arise, as the cylinder containing the flushing agent can be inadvertently over-pressurized. This can result in explosion, causing personal and/or property damage.